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Planting calendar / Downers Grove, IL

Planting calendar for Downers Grove, IL

Station LISLE-MORTON ARBORETUM, IL US (USC00115097) is 2.9 miles away. Median last 32°F 04/28, median first 32°F 10/16. Crop dates below come from University of Illinois Extension. Where the guide uses weeks around a frost date, those weeks are applied to the median 32°F dates because the guide does not name a 10/50/90 level.

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Crops in the cited guide

SowBush beansNorthMay 24 to June 30 · July 30 to Aug. 14CentralMay 10 to June 15 · July 15 to 30SouthApril 26 to June 1 · July 1 to July 15SowBeetsNorthApril 24 to July 30CentralApril 10 to July 15 (Fall crop)SouthMarch 27 to July 30SowBroccoliNorthApril 24 to May 15 · July 15 to 30CentralApril 10 to May 1 · July 1 to 15SouthMarch 27 to April 15 · July 15 to 30SowCabbageNorthApril 24 to July 30CentralApril 10 to July 15 (Fall crop)SouthMarch 18 to July 30SowCarrotsNorthApril 24 to July 30CentralApril 10 to July 15 (Fall crop)SouthMarch 18 to July 30SowSwiss chardNorthApril 24 to May 15 · July 24 to Aug. 10CentralApril 10 to June 1 · July 21 to August 1SouthMarch 27 to May 15 · July 7 to 21SowSweet cornNorthMay 15 to July 1CentralMay 1 to July 1SouthApril 15 to June 25SowCucumberNorthMay 24 to June 30CentralMay 10 to June 15SouthApril 27 to June 1SowEggplantNorthMay 24 to June 30CentralMay 10 to June 15SouthApril 27 to June 1SowGarlicNorthMid-SeptemberCentralOctoberSouthLate OctoberSowKaleNorthApril 14 to May 14 · Aug. 1 to 14CentralApril 1 to 30 · July 21 to Aug. 1SouthMarch 15 to April 15 · July 7 to 18SowLettuceNorthApril 15 to May 15 · July 15 to Sept. 15CentralApril 1 to 30 · July 1 to Aug. 31SouthMarch 15 to April 15 · June 15 to Aug. 15SowOkraNorthMay 24 to June 30CentralMay 10 to June 15SouthApril 26 to June 1SowOnions (green) setsNorthApril 9 to May 15CentralMarch 25 to May 1SouthMarch 11 to April 15SowPeasNorthApril 24 to May 15CentralMarch 12 to May 1SouthMarch 27 to April 15SowPeppersNorthJune 15 to July 30CentralMay 10 to July 15SouthMay 15 to June 30SowPotatoesNorthApril 15 to 30CentralApril 1 to 15SouthMarch 15 to 30SowPumpkinNorthJune 3 to 24CentralMay 10 to June 10SouthMay 5 to 25SowRadishesNorthApril 20 to June 15 · Aug. 15 to Sept. 15CentralApril 5 to June 1 · Aug. 1 to 30SouthMarch 20 to May 15 · July 15 to Aug. 15SowSpinachNorthApril 5 to 30 · Aug. 5 to Sept. 15CentralMarch 25 to April 15 · July 21 to Aug. 30SouthMarch 11 to April 1 · July 7 to Aug. 15SowSummer squashNorthMay 24 to June 30CentralMay 10 to June 15SouthApril 28 to June 1SowWinter squashNorthJune 5 to 15CentralMay 20 to June 1SouthMay 6 to May 15SowTomatoesNorthMay 24 to June 15CentralMay 10 to June 1SouthApril 28 to May 15SowTurnipsNorthMay 15 to Aug. 5 (fall crop)CentralMay 1 to July 21 · July 21 to Aug. 30 (Fall crop)SouthApril 15 to July 7 (fall crop)SowWatermelonNorthMay 24 to July 1CentralMay 10 to June 15SouthApril 28 to June 1

Downers Grove, IL

Zone 6aAverage annual extreme minimum -10°F to -5°F

Median last 32°F is April 28. Median first 32°F is October 16. The 50% growing-season length is 169 days. The green band runs from the median last frost to the median first frost. Thin ticks mark the 10%, 50%, and 90% dates.

Outside the median season Growing seasonTicks: 10%, 50%, and 90%

Illinois. Nearest qualified station: LISLE-MORTON ARBORETUM, IL US (USC00115097), 2.9 miles. Median last 32°F April 28. Median first 32°F October 16. The 50% growing-season length is 169 days.

Open the ZIP page · Crop guides for Illinois

32°F probabilities at this station
10%50%90%
Last 32°F on or afterMay 14April 28April 14
First 32°F on or beforeOctober 1October 16October 29

Column order matches the NCEI file: for the last freeze, 10% is the later date and 90% is the earlier date. How to read the probabilities.

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Planting calendar

Windows below are from University of Illinois Extension, When to Plant, retrieved 2026-10-10. The planting chart is divided into Northern Illinois, Central Illinois, and Southern Illinois. Median dates for the last 32-degree freeze on the same page: Northern Illinois April 8-29; Central Illinois April 8-15; Southern Illinois April 1-8. The page also says southern Illinois can generally start crops two weeks earlier than central Illinois and northern Illinois about two weeks later; the crop rows below are the chart dates, not a recalculation of that sentence.

Date checks use your device’s calendar and appear after the page loads.

State crop pages: Bush beans · Beets · Broccoli · Cabbage · Carrots · Swiss chard · Sweet corn · Cucumber